TNF‐mediated cytotoxicity and resistance in human prostate cancer cell lines

Abstract

BACKGROUND The contribution of TNF receptor (TNF-R) expression was investigated with respect to TNF sensitivity or insensitivity for androgen-dependent and androgen-independent human prostate cancer (PCA) cell lines, respectively. METHODS Flow cytometric analyses using monoclonal antibodies against the 55-kDa receptor (TNF-R1) and the 75-kDa receptor (TNF-R2) indicated that both receptors were expressed on all three cell lines. RESULTS Moreover, expression of TNF-R1 was greater than expression of TNF-R2 in these PCA cells. All three PCA cell lines produced IL-6. However, IL-6 production was enhanced when TNF-insensitive JCA-1 and PC-3 cells, but not TNF-sensitive LNCaP cells, were treated with rTNF (10−9 M). CONCLUSIONS These data suggest that the lack of an antiproliferative effect of rTNF on the androgen-independent PCA cell lines PC-3 and JCA-1 is not due to the failure of these cells to express TNF-R, but may be related to the differences in TNF-mediated IL-6 expression by these PCA cell lines. © 1996 Wiley-Liss, Inc.